Asphalt-based roofing materials, such as roofing shingles, roll roofing, and commercial roofing, are installed on the roofs of buildings to provide protection from the elements and to give the roof an aesthetically pleasing look. Typically, the roofing material is constructed of a substrate, such as a glass fiber mat or an organic felt, an asphalt coating on the substrate, and a protective and/or decorative surface layer of granules of stone, mineral, sand, or other particulate material embedded in the tacky asphalt coating.
Roofing materials are expected to perform and maintain their appearance over time and in various environmental conditions. The American Society of Testing Materials (ASTM) and Underwriters Laboratories (UL) have developed specifications, testing, and ratings for various properties of roof shingles, such as fire resistance, impact resistance, and wind resistance. Shingle manufacturers desire to provide roofing materials that meet or exceed the various standards, such as the ASTM E108 (UL 790), class A rating for fire resistance. ASTM E108 is a fire-test response standard that is used to evaluate roof coverings in both residential and commercial roofing application and covers materials that are used on combustible or noncombustible roof deckings. Class A fire performance under ASTM E108 requires passage of a “burning brand test,” which is meant to simulate a burning tree branch landing on a typical roof.